Makeshift QT: will it work?

This is a discussion on Makeshift QT: will it work? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; -->
I'd think it would be tough to keep the temp because it's a large area with no hood... for example, if you were treating ...

I'd think it would be tough to keep the temp because it's a large area with no hood... for example, if you were treating for Ich and needed to maintain high temps to treat the fish. . . could be wrong, people DO have open-topped tanks.

I really doubt that plastic wrap would work to keep chems from mixing with the water, even if it did stay down, which I don't think it would, the water would still flow under and around it - I've never tried this, so I can't say 100% for sure, but it's definitely not a risk I'd be willing to take with my own fish :)

The plastic bin like a Rubbermaid would be much better than a bathtub for reasons others have mentioned. But this falls short of what this is all for, and that is to observe the fish closely for the several weeks they are in the QT. I find it impossible to observe the fish from above in any sort of container that is not clear on the sides, and that basically means a small glass tank.

If you are keeping relatively small fish, say 4-6 inches and under, a 20g tank is sufficient for QT. Someone mentioned keeping QT and "hospital" tank separate, and I fully agree. I have a 20g permanently running with sand substrate and some plants (culls from the main tanks), with a heater and sponge filter. The heater isn't necessary until the fish are added. But this tank allows me to keep new fish in a settled environment, and I can sit and carefully observe them. They stay in this tank for at least 3 weeks, often 5-6 weeks. Sometimes several months, if they are species that may need more careful adjustment to captive life. I have had some difficult-feeding fish that have adjusted to prepared foods better in this QT than they ever would in the display tanks with competing fish and more space. In the QT I can feed more to ensure they are getting the idea and eating, and it is easier to clean up.

For a hospital, I have a 10g with just a sponge filter and heater, that is on the shelf dry until needed--which fortunately is very rare. I've only used this once in 4 years.

Just one problem though... It is only 56 quarts (14 gallons) and my spare heater is 200w (don't ask it is a long story). Will it stop heating with the internal thermometer when the temperature is high enough? Is it safe to use?

Also, more worrying is a little not on the container stating: This product may contain chemicals known to the state of California to cause cancer and/or birth defects and other reproductive problems. Wash hands after handling this product. BTW it is a ViaAqua heater.

Do I have anything to worry about regarding the heater and my fish?

On another note do I need a filter for the tank? It will only have to house 3 1-1.2" guppies at one time. Will I be okay doing frequent water changes?